The Importance of Scientific and Technical Innovation in the Police Investigation of Gun Crime

My original contribution to knowledge is the assessment of two ballistics analysis systems using the same bullets and cartridge cases to assess interoperability potential. The results are discussed in the context of policing issues representing a multidisciplinary approach to combating gun crime.

Microscopic comparison of bullets and cartridge cases allows inferences to be made that objects bear marks from the same weapon. Parts of this process have been automated. Digital images of objects are stored in a database and correlations undertaken to find potential matches. An expert will decide on the most probable match based upon a range of potential candidates.

All evidence should be utilised to the fullest extent, including data from ballistics systems. The success rate of the most widely used system has been quoted at between 50% and 95% suggesting that links to other crimes remain undiscovered. There are different ballistics systems available but research has only been conducted on one.

There is no interoperability between systems. Data cannot be shared between different systems. An essential pre-requisite to any work on interoperability, is an understanding of the different systems and the data produced. The research aims were to design a methodology to enable the assessment of systems and to produce ammunition that can be used repeatedly as required. The aim was to conduct an experiment with two of the currently available systems.

The results show variance between systems and their accuracy needs improvement. An error rate has been defined and applied to each system. The results suggest that complete interoperability of systems will only be possible with the full cooperation of the manufacturers. A limited form of interoperability focussing on data sharing may be possible. The results have implications for experts using the systems and suggest that a matching standard should be developed to make forensic ballistics analysis an objective discipline.